Online Business or e-business is any kind of business or commercial transaction that includes sharing information across the internet. Commerce constitutes the exchange of products and services between businesses, groups and individuals and can be seen as one of the essential activities of any business.
Muslim should not facilitate unlawful business in any way. Unlawful business include usury, alcohol, pork, non Halal food, gambling, and any business which is forbidden in Islam. The platform which you want to create should not help people to do or invest or take part in unlawful business.
Muslim is not allowed to sell or take part in marketing or selling alcohol or pork. You should refrain putting such unlawful items on your website or platform. If you sell such Haraam items,bayou will be committing a sinful act, and every income from such work is Haraam as well.
You should keep your platform and business activities clean and pure from any Haraam business.
Yes it is allowed to sell the goods of the manufacturer or the whole seller or any supplier in this way as far as you have agreement with them. You will be then allowed to keep your own margin after paying the agreed price to the supplier.
It prohibited to sell alcohol or to promote the selling and consumption of alcohol, or anything else that is haram.
Further to that, if one thinks of one's mission in life as including 'amr b'il-ma'ruf wa nahy 'an al-munkar, then one should actively prevent the advertising and promotion of anything that is harmful.
A Muslim should avoid the aforementioned type of business as it violates the following Qur'anic principles:
1) The duty of enjoying good.
2) The duty of forbidding evil.
3) The prohibition of spreading corruption on earth.
It may be argued that non-Muslims do not hold the same values of Muslims and therefore there would be no harm in allowing them to keep their businesses. However the Qur'an also commands Muslims to invite others to do good by saying "Let there arise out of you a community inviting to good..." (3:104). This in addition to the fact that some Muslims may be influenced to partake such kind of business. It follows that it is not in the best interest of Muslims to permit haram transactions under their allowance and supervision and it should be avoided.
With prayers for your success.